A vehicular resin back door structure comprising: an inner panel that is made of resin and configures an overall frame of a resin back door supported by a vehicle body so as to be capable of opening and closing, and that is formed with an open section used to view toward the vehicle rear at an upper portion of the inner panel; an outer panel that is made of resin and disposed at the periphery of the open section and at the vehicle outside of the inner panel, and that is joined to the inner panel by a first adhesive to form, together with the inner panel, a frame configuration section including an internal closed cross-section portion; and a contact wall portion that configures part of a portion of the inner panel forming the frame configuration section, and that is configured to directly or indirectly contact the vehicle body in a closed state of the vehicular resin back door, characterized by comprising: a glass sheet that is joined to the inner panel configuring the frame configuration section by a second adhesive, and that closes off the open section from the vehicle outside; wherein the frame configuration section comprises a first join section that is disposed facing the glass sheet and that joins the inner panel and the outer panel together; the first join section and the glass sheet are joined together by the second adhesive; the first join section extends parallel to the glass sheet in a cross-section viewed along the length direction of the frame configuration section; the frame configuration section further comprises a second join section that is disposed at the open section side of the first join section and that joins the inner panel and the outer panel together; the second join section extends along a vehicle up-down direction in a cross-section viewed along the length direction of the frame configuration section; and the contact wall portion contacts the vehicle body through a weather strip. an inner panel that is made of resin and configures an overall frame of a resin back door supported by a vehicle body so as to be capable of opening and closing, and that is formed with an open section used to view toward the vehicle rear at an upper portion of the inner panel; an outer panel that is made of resin and disposed at the periphery of the open section and at the vehicle outside of the inner panel, and that is joined to the inner panel by a first adhesive to form, together with the inner panel, a frame configuration section including an internal closed cross-section portion; and a contact wall portion that configures part of a portion of the inner panel forming the frame configuration section, and that is configured to directly or indirectly contact the vehicle body in a closed state of the vehicular resin back door, characterized by comprising: a glass sheet that is joined to the inner panel configuring the frame configuration section by a second adhesive, and that closes off the open section from the vehicle outside; wherein the frame configuration section comprises a first join section that is disposed facing the glass sheet and that joins the inner panel and the outer panel together; the first join section and the glass sheet are joined together by the second adhesive; the first join section extends parallel to the glass sheet in a cross-section viewed along the length direction of the frame configuration section; the frame configuration section further comprises a second join section that is disposed at the open section side of the first join section and that joins the inner panel and the outer panel together; the second join section extends along a vehicle up-down direction in a cross-section viewed along the length direction of the frame configuration section; and the contact wall portion contacts the vehicle body through a weather strip. a glass sheet that is joined to the inner panel configuring the frame configuration section by a second adhesive, and that closes off the open section from the vehicle outside; wherein the frame configuration section comprises a first join section that is disposed facing the glass sheet and that joins the inner panel and the outer panel together; the first join section and the glass sheet are joined together by the second adhesive; the first join section extends parallel to the glass sheet in a cross-section viewed along the length direction of the frame configuration section; the frame configuration section further comprises a second join section that is disposed at the open section side of the first join section and that joins the inner panel and the outer panel together; the second join section extends along a vehicle up-down direction in a cross-section viewed along the length direction of the frame configuration section; and the contact wall portion contacts the vehicle body through a weather strip.