When a male connector housing 30 is inserted into a proximal end portion of an inner surface 37 of a fitting tubular portion 33, a distal end 45 of an outer surface 41 of the male connector housing 30 is brought into abutting engagement with a plurality of first shaking prevention portions 25 formed at the proximal end portion of this inner surface 37. At this time, a distal end 46 of an inner surface 37 of the fitting tubular portion 33 is also brought into abutting engagement with a plurality of second shaking prevention portions 26 formed at a proximal end portion of the outer surface 41 of the male connector housing 30. Thereafter, a force slightly larger than the insertion force applied so far is applied to the connector, so that press-fitted conditions are formed respectively at the first shaking prevention portions 25 and the second shaking prevention portions 26.