Abstract: A non-contact type tonometer is disclosed. It has an arrangement for transfiguring a cornea to be tested by discharging a fluid to it. This first arrangement comprises a rotary solenoid, a cylinder, and a rotary solenoid driving circuit. It also has a second arrangement for detecting the physical quantity showing the transfiguration of the cornea. The second arrangement comprises a radiating optical system and a detecting optical system. It also has a circuit serving as a third arrangement for detecting the flow pressure of the fluid which has a correlation with an intraocular pressure. It has a fourth arrangement for establishing a correlation function curve between the physical quantity and the flow pressure of the fluid based on the information from the second and third arrangements, deducing a flow pressure value corresponding to the preset value of the physical quantity from the correlation function curve, and converting such deduced flow pressure value of the fluid to an intraocular pressure value.