Displacement occurring by external force between a first member (a case, for example) and a second member (an LCD holder, for example) facing the first member is applied to a detection body (an external force detector), and a loading history of the external force (fracture surfaces) is detected by deformation of the detection body occurring when the force exceeds an allowable limit. Provided are a body section and a force receiving section (a head, arms) projected from the body section. The body section is provided between the first member and the second member facing the first member and is supported by either first or second members. The force receiving section deforms when external force acting in the direction crossing a gap between the first and second members or in the direction along the gap exceeds the allowable limit.