An indwelling needle for reducing the deterioration of the valve by the pressure force of the elastic member.A connector part is provided so as to be moveable within the outer needle body connected to the basal portion of the cannula and provided with the space communicating with the lumen of the cannula therein. Also, within the outer needle body, the valve including the opening and closing aperture through which the tip end side portion of the connector part is liquid tightly penetrated to communicate the lumen of the cannula with the flow path of the connector part as well as the space of the front side portion and the rear side portion of the outer needle body are occluded by closing when the tip end side portion of the connector part is not penetrated therethrough.