7d the portable telephone includes a movable case portion 102 which is attached to an upper side case portion 100 formed of a molded body made of synthetic resin by a hinge mechanism the movable case portion being foldable in the direction of an arrow a a sound emitting hole 106 is formed on the upper side case portion 100 for a receiver 104 provided inside the upper side case portion 100 a space 108 is formed on the upper side case portion 100 at the left portion adjacent to the sound emitting hole 106 for installing the electroacoustic transducer therein a display window 110 and a keyboard 112 are provided on the upper side case portion 100 a sound absorbing hole 116 for a microphone 114 is formed on the movable case portion 102 the space 108 is opened to the atmosphere through a sound emitting hole 118 and it includes therein a waterproof sheet 120 and a ring shaped rubber pad 122 which is fixed to the waterproof sheet 120 by a fixing means such as adhesive a board 200 as shown in fig8 a and 8b are provided on the back side of the upper side case portion 100 electronic circuit portions 202 and 204 and a display element 206 for.