Disclosed is a mixer able to simultaneously suppress self-mixing and low-order harmonic response in a charge sampling circuit. Specifically disclosed is a multiphase mixer provided with a transconductance amplifier (101) for converting a voltage signal into a current signal, an N number (where N is a natural number that is 2 or more) of first integrators (401, 402) which are connected in parallel to the subsequent stage of the transconductance amplifier (101), and a 2N number of mixers (102, 103, 104, 105) connected in parallel in pairs to the respective N number of first integrators (401, 402), wherein two mixers connected to the same first integrator of any of the N number of first integrators (401, 402) are controlled by driving signals comprised of pulse trains with the same frequency and phases differing by 180°.