Abstract: A cosmetic composition containing a component (A): a polyglycerol fatty acid ester, which is an ester of polyglycerol having an average degree of polymerization of 3 to less than 100 with a fatty acid having 6 to 30 carbon atoms; a component (B): water; and a component (C): at least one compound selected from the group consisting of ascorbic acid, ascorbic acid derivatives, trehalose, sucrose, citric acid and salts of citric acid, and a cosmetic containing the cosmetic composition.

Abstract: A magnetic disk drive includes a switching regulator configured to generate an output voltage, and a magnetic disk control unit that receives the output voltage as a power supply and performs data write and read operations on a magnetic recording medium. The switching regulator includes a voltage conversion part configured to generate a second voltage by switching a first voltage, a smoothing part configured to smooth the second voltage to thus produce an output voltage, a control part configured to control the switching on the basis of a difference between the output voltage and a reference voltage to thus stabilize the output voltage, and a reference voltage changing part configured to change the reference voltage in accordance with an operation mode of the magnetic disk control unit.

Abstract: A cipher key used for encoding and decoding of data is stored in a cipher key memory unit. A cipher encode unit encodes data input from an upper apparatus via a host interface using the cipher key and records it onto a record medium. A cipher decode unit decodes the encoded data read out from the record medium using the cipher key and outputs it via the host interface to the upper apparatus. When a magnetic disk apparatus is discarded, the decoding is made impossible by changing the cipher key stored in the cipher key memory unit with a cipher key change unit.