A connecting device of the present invention includes a contact and a body which accommodates it. Clamp arms of the contact include bent parts, and hold parts continued from the tips of the bent parts and bent opposite to the bent parts. When piece members of the operation member press the bent parts, the hold parts approach each other and intersect to thereby form a space between them. When the press is released, the hold parts approach each other to thereby close the space, whereby the lead terminal inserted in the space is held between the hold parts.