To cope with the high-speed operation of a train by improving a sealing property while a lid of the electric coupler is closed.

In an electric coupler, an insulating stand in which a plurality of contact pieces are arranged in an opening of a front of a box element 21, and an approximately cylindrical lid 22 retracted above the opening of the front of the box element 21 in coupling, and rotated and lowered around a support shaft in a horizontal direction to close the opening at non-coupling is provided. A gasket 211a attached to the opening is of a shrinkable type expanded and shrunk by inflating or evacuating air. A pressing member 225 brought into close contact with the gasket 211a along the whole circumference is disposed to a rear face, while the gasket 211a is expanded.