A biological signal measuring apparatus that is provided with an oscillatory wave detection apparatus, an oscillatory wave period measuring part, a group memory apparatus that is configured to collect the periodic data and to store the periodic data as a group signal, and a vibration frequency calculation apparatus. The vibration frequency calculation apparatus is provided with a section discrimination part configured to compare the group signal with a predetermined value to carry out a section discrimination, a section memory part configured to store to a plurality of sections, a weight coefficient memory part configured to store a weight coefficient, and an oscillatory wave period weighted average value calculation part.
