first embodiment are obtained by changing the number of light receiving elements that is in the second embodiment plural light receiving element groups different in the number of elements are provided and the plural light receiving element groups output photocurrent in accordance with the number of elements at this time the number of elements in each group is determined such that the same amount of photocurrent is output further in the second embodiment photocurrents output from each light receiving element group are input to different amplifiers these amplifiers are set to have the same characteristics making it possible to amplify output signals of each light receiving element group with the same gain a schematic description about the second embodiment is given below with reference to fig5 and 6 fig5 is a schematic diagram of the configuration of the optical pickup device and the light amount detecting circuit fig6 is a schematic diagram of a circuit configuration example of the optical pickup device and the light amount detecting circuit as shown in fig5 the optical pickup device 10 includes plural light receiving elements more specifically the plural light receiving elements are divided into light receiving element groups 303 having more elements and light receiving element groups 304 having fewer elements the light receiving element groups 303 and 304 are radially arranged each group more specifically the light receiving element groups 303 and 304 are alternately arranged along the circumference for example the number of light receiving element groups 303 having more elements may be set 10 times larger than the.