The sensor inserting device (10) includes a device main body (16) and a push handle (18) for moving a detector (36) of a sensor (12) and an insertion needle (30), with the sensor (12) held together with the insertion needle (30) in a held state, to insert the detector (36) of the sensor (12) and the insertion needle (30) into the body of a patient. A transmitter (14) for processing a signal from the sensor (12) is set in the device main body (16). A cable (34), allowing transmission of a signal between the sensor (12) in the held state and the transmitter (14) by setting the transmitter (14), is connected to the sensor (12).