A device support system comprising a portable device, and a support device for supporting the portable device, wherein: the portable device comprises: a generally plate-shaped housing with a hole formed therein; and a first terminal provided on a surface of the housing on which the hole is formed; and the support device comprises: a second terminal which can be connected to the first terminal; a support member which supports a predetermined surface of the housing when the first terminal and the second terminal are connected to each other; a rotating member (213a, 213b) which can rotate in a predetermined direction and which is provided at such a position that the rotating member is inserted into the hole when the first terminal and the second terminal are connected to each other; characterized by a groove portion into which a portion of the housing is inserted when the first terminal and the second terminal are connected to each other, wherein the rotating member is provided so that a portion thereof projects from a bottom surface of the groove portion. the portable device comprises: a generally plate-shaped housing with a hole formed therein; and a first terminal provided on a surface of the housing on which the hole is formed; and the support device comprises: a second terminal which can be connected to the first terminal; a support member which supports a predetermined surface of the housing when the first terminal and the second terminal are connected to each other; a rotating member (213a, 213b) which can rotate in a predetermined direction and which is provided at such a position that the rotating member is inserted into the hole when the first terminal and the second terminal are connected to each other; characterized by a groove portion into which a portion of the housing is inserted when the first terminal and the second terminal are connected to each other, wherein the rotating member is provided so that a portion thereof projects from a bottom surface of the groove portion. a generally plate-shaped housing with a hole formed therein; and a first terminal provided on a surface of the housing on which the hole is formed; and the support device comprises: a second terminal which can be connected to the first terminal; a support member which supports a predetermined surface of the housing when the first terminal and the second terminal are connected to each other; a rotating member (213a, 213b) which can rotate in a predetermined direction and which is provided at such a position that the rotating member is inserted into the hole when the first terminal and the second terminal are connected to each other; characterized by a groove portion into which a portion of the housing is inserted when the first terminal and the second terminal are connected to each other, wherein the rotating member is provided so that a portion thereof projects from a bottom surface of the groove portion. a second terminal which can be connected to the first terminal; a support member which supports a predetermined surface of the housing when the first terminal and the second terminal are connected to each other; a rotating member (213a, 213b) which can rotate in a predetermined direction and which is provided at such a position that the rotating member is inserted into the hole when the first terminal and the second terminal are connected to each other; characterized by a groove portion into which a portion of the housing is inserted when the first terminal and the second terminal are connected to each other, wherein the rotating member is provided so that a portion thereof projects from a bottom surface of the groove portion.