A control circuit for a distance measuring system configured to measure a distance to an object by emitting light and receiving reflected light from the object by means of the Time-of-Flight method, the control circuit comprising: a passive circuit configured to: supply current to a Single Photon Avalanche Diode, SPAD, element, from a single supply path (Rp), the SPAD being configured to receive the reflected light from the object,; and output a first pulse signal according to a signal generated in the SPAD element; an active circuit configured to: supply current to the SPAD element selectively from among a plurality of supply paths (Ra1, Ra2); and output a second pulse signal according to a signal generated in the SPAD element, the active circuit including: a first supply path that supplies current to the SPAD element while avalanche amplification is occurring in the SPAD element; and a second supply path that supplies current to the SPAD element after avalanche amplification is stopped in the SPAD element; and a control unit that controls the passive circuit and the active circuit, characterized in that the control unit switches a circuit connected to the SPAD element between the passive circuit and the active circuit in accordance with a number of counts per frame of one of the first pulse signal and the second pulse signal output from corresponding one of the passive circuit and the active circuit, wherein the control unit selects the passive circuit when the number of counts is smaller than a number of threshold counts (Cth), and selects the active circuit when the number of counts is equal to or more than the number of threshold counts (Cth). a passive circuit configured to: supply current to a Single Photon Avalanche Diode, SPAD, element, from a single supply path (Rp), the SPAD being configured to receive the reflected light from the object,; and output a first pulse signal according to a signal generated in the SPAD element; supply current to a Single Photon Avalanche Diode, SPAD, element, from a single supply path (Rp), the SPAD being configured to receive the reflected light from the object,; and output a first pulse signal according to a signal generated in the SPAD element; an active circuit configured to: supply current to the SPAD element selectively from among a plurality of supply paths (Ra1, Ra2); and output a second pulse signal according to a signal generated in the SPAD element, the active circuit including: a first supply path that supplies current to the SPAD element while avalanche amplification is occurring in the SPAD element; and a second supply path that supplies current to the SPAD element after avalanche amplification is stopped in the SPAD element; and supply current to the SPAD element selectively from among a plurality of supply paths (Ra1, Ra2); and output a second pulse signal according to a signal generated in the SPAD element, the active circuit including: a first supply path that supplies current to the SPAD element while avalanche amplification is occurring in the SPAD element; and a second supply path that supplies current to the SPAD element after avalanche amplification is stopped in the SPAD element; and a first supply path that supplies current to the SPAD element while avalanche amplification is occurring in the SPAD element; and a second supply path that supplies current to the SPAD element after avalanche amplification is stopped in the SPAD element; and a control unit that controls the passive circuit and the active circuit, characterized in that the control unit switches a circuit connected to the SPAD element between the passive circuit and the active circuit in accordance with a number of counts per frame of one of the first pulse signal and the second pulse signal output from corresponding one of the passive circuit and the active circuit, wherein the control unit selects the passive circuit when the number of counts is smaller than a number of threshold counts (Cth), and selects the active circuit when the number of counts is equal to or more than the number of threshold counts (Cth).