Abstract: An electric circuit apparatus comprises a long and narrow case having two openings at both longitudinal ends thereof, a long and narrow circuit board contained in the case, on which electrical parts are attached and in which an electric circuit connected to the parts is mounted, and a pair of terminal bases mounted at the two openings within the case and each including at least one external connecting terminal externally opened in the longitudinal direction of the case. The terminal bases support both longitudinal ends of the circuit board and have the external connecting terminal connected to the electric circuit of the circuit board. The electrical parts are positioned within the respective height ranges of the terminal bases.