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 . <EOS>