A booster cable holding structure includes a clamping connection portion configured to be clamped by a clip portion of a booster cable. The clamping connection portion includes a relief terminal portion protruding in a tabular manner from a base structure made of insulating resin, and a terminal supporting resin portion extending in a tabular manner from the base structure over a surface of the relief terminal portion. The terminal supporting resin portion has a groove into which at least one tooth of the clip portion enters when the clip portion clamps the clamping connection portion, and a movement restricting wall configured to block a movement of the clip portion. The movement restricting wall is provided on a side toward which the clip portion having the tooth entered the groove is moved along the groove by an external force that pulls a cable of the booster cable.