Abstract: A method for producing a plastic element provided with fine surface roughness is provided. In the method, etching of a surface of the plastic element is performed separately in a first step and in a second step, in the first step, fine roughness having a predetermined average value of pitch in the range from 0.05 to 1 micrometer is generated on the surface through reactive ion etching in an atmosphere of a first gas; and in the second step, an average value of depth of the fine roughness generated in the first step is adjusted to a predetermined value in the range from 0.15 to 1.5 micrometers while the predetermined average value of pitch is substantially maintained through reactive ion etching in an atmosphere of a second gas, reactivity to the plastic element of the second gas being lower than reactivity to the plastic element of the first gas.

Abstract: A method for manufacturing fine surface roughness having an average pitch of 50 nanometers to 5 micrometers on a quartz glass substrate without preparing a mask prior to an etching process, the method comprising the steps of: making the quartz glass substrate undergo ion etching with argon gas in an ion etching apparatus, in which the quartz glass substrate is placed on a first electrode, the first electrode is connected to a high frequency power source and a second electrode is grounded; and making the quartz glass substrate undergo reactive ion etching with trifluoromethane (CHF3) gas or a mixed gas of trifluoromethane (CHF3) and oxygen in the ion etching apparatus in which the quartz glass substrate is placed on the first electrode, the first electrode is connected to the high frequency power source and the second electrode is grounded.

Abstract: A method for producing a plastic element provided with fine surface roughness is provided. In the method, etching of a surface of the plastic element is performed separately in a first step and in a second step, in the first step, fine roughness having a predetermined average value of pitch in the range from 0.05 to 1 micrometer is generated on the surface through reactive ion etching in an atmosphere of a first gas; and in the second step, an average value of depth of the fine roughness generated in the first step is adjusted to a predetermined value in the range from 0.15 to 1.5 micrometers while the predetermined average value of pitch is substantially maintained through reactive ion etching in an atmosphere of a second gas, reactivity to the plastic element of the second gas being lower than reactivity to the plastic element of the first gas.