A connector comprising: a connector housing including a connector fitting chamber to which a mating connector is fittable, in which a power terminal is arranged in a projecting state in the connector fitting chamber; a rear case that covers a back side of the connector housing opposite to a side on which the mating connector is fittable, and is assembled to the connector housing through intermediation of a first waterproof member; a water drainage passage (18, 19) provided in the connector housing, which allows water that has entered the side of the connector housing on which the mating connector is fittable to flow into an inside of the rear case; a drainage port provided in the rear case, which is configured to drain water inside the rear case to an outside; a terminal accommodating portion that holds the terminal in the projecting state in the connector fitting chamber at an insertion completion position and has an opening portion on a back side of the rear case; and a second waterproof member attached to an outer periphery of the power terminal to be interposed between an inner peripheral surface of the terminal accommodating portion on a side of the rear case and an outer peripheral surface of the terminal, wherein the terminal accommodating portion includes a terminal holding wall provided in the rear case extending from the front side to the back side of the rear case and holding the power terminal, wherein the terminal holding wall includes the opening portion and an accommodating chamber having diameters in which the power terminal is accommodated without a gap characterized in that the terminal holding wall further includes a taper chamber gradually expanding from the accommodating chamber, and a large-diameter chamber having diameters in which the power terminal is inserted with a gap, wherein the back surface end of the large-diameter chamber is the opening portion, wherein a C-ring is attached to the power terminal, the connector is configured such that the power terminal is inserted from the opening portion, the C-ring attached to the power terminal is contracted when passing through the taper chamber and insertion to the insertion completion position is permitted, where the C-ring expands and enters a recess of the terminal holding wall such that the power terminal is positioned and fixed to the terminal accommodating portion, and the second waterproof member is in close contact with the inner peripheral surface of the terminal holding wall in a compressed state. a connector housing including a connector fitting chamber to which a mating connector is fittable, in which a power terminal is arranged in a projecting state in the connector fitting chamber; a rear case that covers a back side of the connector housing opposite to a side on which the mating connector is fittable, and is assembled to the connector housing through intermediation of a first waterproof member; a water drainage passage (18, 19) provided in the connector housing, which allows water that has entered the side of the connector housing on which the mating connector is fittable to flow into an inside of the rear case; a drainage port provided in the rear case, which is configured to drain water inside the rear case to an outside; a terminal accommodating portion that holds the terminal in the projecting state in the connector fitting chamber at an insertion completion position and has an opening portion on a back side of the rear case; and a second waterproof member attached to an outer periphery of the power terminal to be interposed between an inner peripheral surface of the terminal accommodating portion on a side of the rear case and an outer peripheral surface of the terminal, wherein the terminal accommodating portion includes a terminal holding wall provided in the rear case extending from the front side to the back side of the rear case and holding the power terminal, wherein the terminal holding wall includes the opening portion and an accommodating chamber having diameters in which the power terminal is accommodated without a gap characterized in that the terminal holding wall further includes a taper chamber gradually expanding from the accommodating chamber, and a large-diameter chamber having diameters in which the power terminal is inserted with a gap, wherein the back surface end of the large-diameter chamber is the opening portion, wherein a C-ring is attached to the power terminal, the connector is configured such that the power terminal is inserted from the opening portion, the C-ring attached to the power terminal is contracted when passing through the taper chamber and insertion to the insertion completion position is permitted, where the C-ring expands and enters a recess of the terminal holding wall such that the power terminal is positioned and fixed to the terminal accommodating portion, and the second waterproof member is in close contact with the inner peripheral surface of the terminal holding wall in a compressed state.