A non-surgical sensor insertion method for inserting a sensor into a user's body, the sensor being a continuous glucose monitoring sensor (CGMS), the method comprising: an attaching step of attaching the sensor to a unit base; a unit fixing step of regulating a relative position between a sensor control unit and an inserting unit, the sensor control unit being fixed inside the inserting unit and being in a sensor insertion allowing state, the inserting unit containing the sensor therein, and of fixing the sensor control unit and the inserting unit to an insertion target portion of the user; a sensor inserting step of causing the inserting unit to insert the sensor, which is attached to the unit base, into the insertion target portion; a fixing step of fixing the unit base and thereby also the sensor, which is attached to the unit base, in a state that the sensor is inserted into the insertion target portion of the user; and a sensor connecting step of shifting the sensor control unit from the sensor insertion allowing state to a sensor connecting state, thereby establishing electrical conduction between the sensor in the insertion target portion and the sensor control unit, wherein, in the sensor connecting step, the sensor and the sensor control unit are electrically connected to each other by rotating of the sensor control unit, via an engagement portion configured to allow for rotatable engagement of sensor control unit and the unit base, the engagement portion provided either on the sensor control unit, or the unit base, or on both; wherein the sensor control unit rotatably engages with the unit base by moving of the inserting unit along the insertion target portion. an attaching step of attaching the sensor to a unit base; a unit fixing step of regulating a relative position between a sensor control unit and an inserting unit, the sensor control unit being fixed inside the inserting unit and being in a sensor insertion allowing state, the inserting unit containing the sensor therein, and of fixing the sensor control unit and the inserting unit to an insertion target portion of the user; a sensor inserting step of causing the inserting unit to insert the sensor, which is attached to the unit base, into the insertion target portion; a fixing step of fixing the unit base and thereby also the sensor, which is attached to the unit base, in a state that the sensor is inserted into the insertion target portion of the user; and a sensor connecting step of shifting the sensor control unit from the sensor insertion allowing state to a sensor connecting state, thereby establishing electrical conduction between the sensor in the insertion target portion and the sensor control unit, wherein, in the sensor connecting step, the sensor and the sensor control unit are electrically connected to each other by rotating of the sensor control unit, via an engagement portion configured to allow for rotatable engagement of sensor control unit and the unit base, the engagement portion provided either on the sensor control unit, or the unit base, or on both; wherein the sensor control unit rotatably engages with the unit base by moving of the inserting unit along the insertion target portion.