In the present invention, a protective cover is provided with, a base bottom portion and a cover portion which is disposed in the base bottom portion through a hinge. The protective cover can be attached to a connector so as to be fitted with a through-lock portion of the connector and the cover portion is then closed. The base bottom portion is formed in a gutter-shape and the rear end side of the base bottom portion is partially closed by a closing portion. In the present invention, a protective cover is also provided with, a cylindrical cover main body to be fitted with a connector, and a pair of opening-and-closing members disposed on the cover main body through hinges. The protective cover further includes securing holes for securing the opening-and-closing members to securing projections disposed on the cover main body, and securing pawls and securing frames for engaging the opening-and-closing members with each other.