The load detector includes: first and second beam type load cells which are supported on first and second support bases in a cantilever manner to have free ends; and a mounting part on which an object is to be placed, which includes first and second connection parts connected to the first and second beam type load cells, and which is disposed between the first and second beam type load cells. The free ends of the first and second beam type load cells face opposite directions to each other in an extending direction of the first beam type load cell. The first and second connection parts of the mounting part are respectively connected to the first and second beam type load cells on a side of the free ends of the first and second beam type load cells.