In a mobile phone device 1 including a three-axial direction vibration sensor 16 for detecting the walking of a user carrying the mobile phone device 1 and counting the number of walking steps, when an incoming call is received, vibrations due to a notification operation by a vibrator 14 or a speaker 15 are transmitted to the three-axial direction vibration sensor 16. As a result, the three-axial direction vibration sensor 16 inevitably detects unintended vibrations in addition to vibrations from walking, causing the number of walking steps to be miscounted. To prevent this and perform the accurate detection of walking, in the present invention, the detection of walking is performed without using, among vibrations in three directions detected by the three-axial direction vibration sensor 16, vibrations in the same direction as the direction of vibrations caused by a notification operation by the vibrator 14 or the speaker 15.