A tape cassette, comprising: a box-like cassette case having a first outer wall, a second outer wall, a third outer wall, a fourth outer wall, a fifth outer wall and a sixth outer wall, the first outer wall and the second outer wall extending in parallel and being arranged in a first direction perpendicular to both the first outer wall and the second outer wall, the third outer wall and the fourth outer wall extending in parallel and being arranged in a second direction perpendicular to both the third outer wall and the fourth outer wall, the fifth outer wall and the sixth outer wall extending in parallel and being arranged in a third direction perpendicular to both the fifth outer wall and the sixth outer wall, the first direction, the second direction and the third direction are perpendicular to each other; a tape (6, 7) configured to be accommodated in the cassette case; and a substrate having a first surface and a second surface opposite to the first surface, a pair of conductive electrodes being provided to the first surface, a storage electrically connected to the pair of conductive electrodes being provided to the second surface, the third outer wall has a first side wall extending in parallel with the third outer wall, one of a recess and a hole being provided, the recess being recessed in a fourth direction, which is a one-way direction of the second direction directing inside the cassette case from the third outer wall, and the hole penetrating the cassette case in the second direction, and a second side wall extending in parallel with the third outer wall, the first side wall, the one of the recess and the hole, and the second side wall extending, in this order, along a fifth direction which is a one-way direction of the third direction, the pair of conductive electrodes being arranged in a sixth direction which is parallel with the first surface, given that the second surface is equally divided into three areas of a first substrate area, a second substrate area and a third substrate area, in this order, along a one-way direction of the sixth direction, the storage being arranged in the second substrate area, the second surface of the substrate being arranged to be bridged between the first side wall and the second side wall with the third direction being the sixth direction and a seventh direction opposite to the fourth direction being directed to the first surface; and one of the storage and a molded part protecting the storage being arranged at the one of the recess and the hole. a box-like cassette case having a first outer wall, a second outer wall, a third outer wall, a fourth outer wall, a fifth outer wall and a sixth outer wall, the first outer wall and the second outer wall extending in parallel and being arranged in a first direction perpendicular to both the first outer wall and the second outer wall, the third outer wall and the fourth outer wall extending in parallel and being arranged in a second direction perpendicular to both the third outer wall and the fourth outer wall, the fifth outer wall and the sixth outer wall extending in parallel and being arranged in a third direction perpendicular to both the fifth outer wall and the sixth outer wall, the first direction, the second direction and the third direction are perpendicular to each other; the first outer wall and the second outer wall extending in parallel and being arranged in a first direction perpendicular to both the first outer wall and the second outer wall, the third outer wall and the fourth outer wall extending in parallel and being arranged in a second direction perpendicular to both the third outer wall and the fourth outer wall, the fifth outer wall and the sixth outer wall extending in parallel and being arranged in a third direction perpendicular to both the fifth outer wall and the sixth outer wall, the first direction, the second direction and the third direction are perpendicular to each other; a tape (6, 7) configured to be accommodated in the cassette case; and a substrate having a first surface and a second surface opposite to the first surface, a pair of conductive electrodes being provided to the first surface, a storage electrically connected to the pair of conductive electrodes being provided to the second surface, the third outer wall has a first side wall extending in parallel with the third outer wall, one of a recess and a hole being provided, the recess being recessed in a fourth direction, which is a one-way direction of the second direction directing inside the cassette case from the third outer wall, and the hole penetrating the cassette case in the second direction, and a second side wall extending in parallel with the third outer wall, the first side wall, the one of the recess and the hole, and the second side wall extending, in this order, along a fifth direction which is a one-way direction of the third direction, the pair of conductive electrodes being arranged in a sixth direction which is parallel with the first surface, given that the second surface is equally divided into three areas of a first substrate area, a second substrate area and a third substrate area, in this order, along a one-way direction of the sixth direction, the storage being arranged in the second substrate area, the second surface of the substrate being arranged to be bridged between the first side wall and the second side wall with the third direction being the sixth direction and a seventh direction opposite to the fourth direction being directed to the first surface; and one of the storage and a molded part protecting the storage being arranged at the one of the recess and the hole.