A terminal structure has: a plurality of connecting terminals (11) provided in a row arrangement; elongated holes (11a) provided on these connecting terminals (11) for terminal screws to pass through and elongated in the direction of the connecting terminal row arrangement; and terminal screws (13) that pass through the elongated holes (11a) and nuts (14) threadably mounted thereon. The constitution is such that when L0 is defined as the distance between a pair of surfaces that stop the turning of a nut (14) provided parallel to the direction of movement of a terminal screw (13) along an elongated hole (11a) in a space that accommodates a nut (14) provided in a base (1), L1 the distance between the vertex of a certain one corner provided on the nut (14) and the vertex of a corner in opposition thereto, and L2 the distance between a pair of surfaces of the nut (14) provided parallel to the direction of movement of the terminal screw (13) along the elongated hole (11a), L0 - L2 is 0.2 mm or greater and L1/L0 is 1.33 or greater.