A mobile device includes an acceleration sensor, a touch screen and a controller. The acceleration sensor is capable of detecting a direction and a magnitude of acceleration acting on the mobile device. The touch screen is capable of measuring electrostatic distribution. The controller is capable of executing an estimation whether the mobile device is being immersed in water based on the electrostatic distribution. The controller periodically executes the estimation upon determining that the mobile device is moving in a direction opposite to a gravity direction based on the direction and the magnitude of the acceleration when estimating that the mobile device is being immersed in water.