A lid lock apparatus for a vehicle, comprising: a housing; a drive motor accommodated within the housing; an output gear supported within the housing to be rotatable by means of an operation of the drive motor; and a shaft member axially movably supported within the housing, one end of the shaft member being engageable with a lid member provided at a vehicle body by projecting from the housing, the shaft member axially moving by engaging with the output gear; wherein the output gear includes an engagement piece extending in a thickness direction of the housing and engaging with the shaft member, the shaft member includes a support portion movably supported by the housing, a relief portion cut out in the thickness direction and on which the output gear is placed in an overlapping manner in the thickness direction, and a recess portion into which the engagement piece of the output gear is inserted in the thickness direction, and wherein the lid lock apparatus is characterized by comprising: a contact portion formed at least at one of the engagement piece and the recess portion; the contact portion being obtained by a portion of the engagement piece closest to an axial center of the shaft member in the thickness direction extending radially outwardly relative to the other portion of the engagement piece, in a case where the contact portion is formed at the engagement piece; the contact portion being obtained by a portion of the recess portion closest to the axial center of the shaft member in the thickness direction extending radially inwardly relative to the other portion of the recess portion, in a case where the contact portion is formed at the recess portion; so that the engagement piece and the recess portion engage with each other at the axial center of the shaft member passing through a center of the support portion in the thickness direction in a case where the shaft member axially moves. a housing; a drive motor accommodated within the housing; an output gear supported within the housing to be rotatable by means of an operation of the drive motor; and a shaft member axially movably supported within the housing, one end of the shaft member being engageable with a lid member provided at a vehicle body by projecting from the housing, the shaft member axially moving by engaging with the output gear; wherein the output gear includes an engagement piece extending in a thickness direction of the housing and engaging with the shaft member, the shaft member includes a support portion movably supported by the housing, a relief portion cut out in the thickness direction and on which the output gear is placed in an overlapping manner in the thickness direction, and a recess portion into which the engagement piece of the output gear is inserted in the thickness direction, and wherein the lid lock apparatus is characterized by comprising: a contact portion formed at least at one of the engagement piece and the recess portion; the contact portion being obtained by a portion of the engagement piece closest to an axial center of the shaft member in the thickness direction extending radially outwardly relative to the other portion of the engagement piece, in a case where the contact portion is formed at the engagement piece; the contact portion being obtained by a portion of the recess portion closest to the axial center of the shaft member in the thickness direction extending radially inwardly relative to the other portion of the recess portion, in a case where the contact portion is formed at the recess portion; so that the engagement piece and the recess portion engage with each other at the axial center of the shaft member passing through a center of the support portion in the thickness direction in a case where the shaft member axially moves. a contact portion formed at least at one of the engagement piece and the recess portion; the contact portion being obtained by a portion of the engagement piece closest to an axial center of the shaft member in the thickness direction extending radially outwardly relative to the other portion of the engagement piece, in a case where the contact portion is formed at the engagement piece; the contact portion being obtained by a portion of the recess portion closest to the axial center of the shaft member in the thickness direction extending radially inwardly relative to the other portion of the recess portion, in a case where the contact portion is formed at the recess portion; so that the engagement piece and the recess portion engage with each other at the axial center of the shaft member passing through a center of the support portion in the thickness direction in a case where the shaft member axially moves.