Connector, electric wire with connector, and medical device sensor

An object of the present invention is to provide a connector into which a mating terminal pin is easily inserted and of which it is hardly pulled out, an electric wire with the connector, and a medical device sensor that includes the electric wire with the connector. The present invention provides a connector including: a connector terminal including a terminal base portion to which an electric wire is connectable, and an electric connector to which the mating terminal pin is connected; and a connector housing including a terminal housing portion. The terminal housing portion includes a tubular inner surface surrounding the electric connector. The electric connector includes flat plate-shaped elastic contact pieces arranged at intervals from each other around a central axis of the tubular inner surface. Each of the elastic contact pieces includes: a contact portion that extends along the central axis and is curved; a base portion for restricting the contact portion from moving; and a distal end portion positi