A solid-state image pickup apparatus 1A includes a photodetecting section 10A, a signal readout section 20, and a controlling section 40A. In the photodetecting section 10A, M×N pixel units P1,1 to PM,N each including a photodiode and a readout switch are arrayed in M rows and N columns. Charges generated in each pixel unit Pm,n are input to an integrating circuit Sn through a readout wiring LO,n, and a voltage value output from the integrating circuit Sn in response to the charge amount is output through a holding circuits Hn. When in a first imaging mode, a voltage value according to an amount of charges generated in the photodiode PD of each of the M×N pixel units P1,1 to PM,N in the photodetecting section 10A is output from the signal readout section 20. When in a second imaging mode, a voltage value according to an amount of charges generated in the photodiode PD of each pixel unit Pm,n included in consecutive M1 rows in the photodetecting section 10A is output from the signal readout section 20.