PURPOSE: To reduce the number of pieces of operational amplifiers, and to attain low power consumption by making the switched capacitor filter into configuration in which a sample hold circuit is omitted at an input side.

CONSTITUTION: The switched capacitor filter is constituted of a first operational amplifier 8, a second operational amplifier 15, a first SC (switched capacitor) circuit between an input terminal 1 and the input side of the operational amplifier 8, a second SC circuit between the terminal 1 and the input side of the amplifier 15, a third SC circuit between the output side of the amplifier 15 and the input side of the amplifier 8, a fourth SC circuit between the terminal 1 and the input side of the amplifier 15, and a fifth SC circuit between the output side of the amplifier 8 and the input side of the amplifier 15. Through this configuration, by using such the SC circuit as to be constituted of capacitors 27, 28 and switches 29 to 33, all the capacitors 7, 14, 17, 27, 28, 9 to charge an input signal in the filter charge the input signal at the same point of time at every sampling period. Accordingly, the same effect as in the case that the input signal is sample-held can be obtained, and the sample hold circuit at the input side can be omitted.