The present invention provides a sensor insertion and removing device which is user-friendly and which does not cause infection. The sensor insertion and removing device has a sensor a puncture blade member a housing which houses the sensor and the puncture blade member a guide part which is provided within the housing and which glidably supports the puncture blade member a puncture blade operating part which inserts the sensor under the skin by causing the puncture blade member to glide along the guide part integrally with the sensor, upon delivering the puncture blade member outside the housing to puncture the skin, and which causes the puncture blade member to glide along the guide part in a state of being separated from the sensor, upon removing the puncture blade member from under the skin into the housing, and a sensor operating part which pulls out the sensor from under the skin and removes it from under the skin into the housing.
