A clock switching circuit in which one clock signal is selected from 2N-phase input clock signals with the same frequency but with each shifted in phase (where N is an integer equal to or greater than 3), based on N-bit selection signals, and is output as an output clock signal, comprises a selector group having 2N−1 selectors each of which select and output one clock signal from two input clock signals, and an operation control circuit which generates 2N−1 operation control signals to execute control to set the 2N−1 selectors into an active state or into a sleep state. The selectors select the clock signals based on the selection signals. The operation control circuit executes control to set a portion of the selectors among the 2N−1 selectors to the active state and to set the remaining selectors to the sleep state, based on the selection signals.