Folding protable information terminal and its state notice method and program

A foldable type portable information terminal can accurately recognize operation mode in a construction having various of functions and various relative attitudes. The portable information terminal includes the upper unit having the display screen in either of the upper or lower surfaces and the lower unit having the operation surface in either upper or lower surfaces coupled for opening and closing and for pivoting. The portable information terminal has a detector which detects variation of relative attitude of the upper unit and the lower unit, for externally announcing variation of relative attitude of the upper unit and the lower unit as detected by the detector.