1. A housing comprising:a first member that has a first conductor;
a second member that has a second conductor and cooperates with the first member to accommodate a circuit board on which an electronic element is mounted, inside a space surrounded by the first conductor and the second conductor; and
a plurality of connecting elements that are arranged at a predetermined arrangement interval y to fix the second member to the first member,
wherein, when an overlapping width between the first conductor and the second conductor is x, a frequency of a clock signal flowing through the circuit board is f, a speed of light is c, and a wavelength of electromagnetic noise is ?=c/f, a value of the arrangement interval y is calculated by following equation (1) or (2),
when x?2.2 mm, y?(0.13x+0.0015)? (1)
when x>2.2 mm, y=(10?5x3?0.0006x2+0.012x+0.25)? (2).