It is an object to provide an apparatus for inspecting a circuit board and a method of inspecting a circuit board which can well absorb a variation in a height of an electrode to be inspected in a circuit board to be inspected and can maintain an insulating property between adjacent inspection electrodes even if the electrode to be inspected is arranged at a fine pitch. An intermediate holding plate 36 is provided in a relay pin unit 31, and a first abutment support position 38A of a first support pin 33 disposed between a first insulating plate 34 and the intermediate holding plate 36 with respect to the intermediate holding plate and a second abutment support position 38B of a second support pin 37 disposed between a second insulating plate 35 and the intermediate holding plate 36 with respect to the intermediate holding plate 36 are placed differently from each other over an intermediate holding plate projecting surface which is projected in a direction of a thickness of the intermediate holding plate 36. Moreover, a relay board 29 having a plurality of rigid conductor electrodes penetrating through the board which is held to be movable in a direction of a thickness of the board is disposed on the side of a circuit board to be inspected in a board 23 for pitch conversion, and furthermore, thin anisotropically conductive sheets 22 and 22 of a dispersion type are provided on both sides thereof and an electrical connection of the board 23 for pitch conversion and a circuit board 1 to be inspected is relayed by means of the relay board 29 through the anisotropically conductive sheets 22 and 22 of a dispersion type.