PURPOSE: To provide ease of built-in work by a method wherein an attitude detector, in which a ball in a ball housing shields off a path of light when the ball is located on another side, is attached on a circuit board where circuit parts of a control circuit are arranged, and the circuit substrate is built in a handle of an iron which is kept horizontally.

CONSTITUTION: In an attitude detector 16, a ball 23 is housed free to move in a ball housing 22 which is located in the top middle on the front half side of a base 21 with a bottom declining toward the front side. On the outer side of the ball housing 22, a light emitting part 26 where a light emitting element PD is housed and a light receiving part 27 where a light receiving circuit PIC is housed are built in the base 21 facing each other across the ball housing 22 and open grooves 24 and 25. The attitude detector 16 is mounted on a circuit board 15 so that the one side of the attitude detector faces the front of an iron A. Parts that compose a control circuit, and the attitude detector 16 are mounted on the circuit board 15, and the two sides of the substrate 15 are fitted and fixed is recessed parts 17 of fixtures 18 which are attached in a handle 12 of the iron A. Thus, the attitude detector 16 can be built-in the iron A, so that built-in work becomes easy.