A handle device comprising: a handle case (20;120) which is disposed on a member on a vehicle body side, the handle case (20;120) including a vertical wall portion which faces a vehicle body panel and a peripheral wall portion (22;122) which is connected to a peripheral edge of the vertical wall portion and surrounded by an interior trim mounted on a vehicle cabin interior side of the vehicle body panel; a cylindrical pin (60;160) which is supported by the handle case (20;120); and an operation member which is housed in the handle case (20;120) and is pivotally supported by the pin (60;160) so as to be rotatable, wherein the handle case (20;120) includes a pin insertion hole (25c1) into which the pin (60;160) is configured to be inserted from an outer side of the handle case (20;120), and a rib (30;130) which is provided to face a head portion of the pin (60;160) inserted into the pin insertion hole (25c1) and prevents the pin (60;160) from slipping off, and wherein the rib (30;130) extends from the handle case (20;120) along an in-plane direction of a case region around the pin insertion hole (25c1), and includes an elastic piece (31;131) which is configured to be elastically deformed in a direction orthogonal to an insertion direction of the pin (60;160), wherein the rib (30;130) is provided on the peripheral wall portion (22;122) of the handle case (20;120) so as to face the head portion of the pin (60;160) inserted into the pin insertion hole (25c1), wherein the pin insertion hole (25c1) is provided in the peripheral wall portion (22;122) of the handle case (20;120), and a base end portion (31a;131a) of the elastic piece (31;131) is connected to the peripheral wall portion (22;122). a handle case (20;120) which is disposed on a member on a vehicle body side, the handle case (20;120) including a vertical wall portion which faces a vehicle body panel and a peripheral wall portion (22;122) which is connected to a peripheral edge of the vertical wall portion and surrounded by an interior trim mounted on a vehicle cabin interior side of the vehicle body panel; a cylindrical pin (60;160) which is supported by the handle case (20;120); and an operation member which is housed in the handle case (20;120) and is pivotally supported by the pin (60;160) so as to be rotatable, wherein the handle case (20;120) includes a pin insertion hole (25c1) into which the pin (60;160) is configured to be inserted from an outer side of the handle case (20;120), and a rib (30;130) which is provided to face a head portion of the pin (60;160) inserted into the pin insertion hole (25c1) and prevents the pin (60;160) from slipping off, and wherein the rib (30;130) extends from the handle case (20;120) along an in-plane direction of a case region around the pin insertion hole (25c1), and includes an elastic piece (31;131) which is configured to be elastically deformed in a direction orthogonal to an insertion direction of the pin (60;160), wherein the rib (30;130) is provided on the peripheral wall portion (22;122) of the handle case (20;120) so as to face the head portion of the pin (60;160) inserted into the pin insertion hole (25c1), wherein the pin insertion hole (25c1) is provided in the peripheral wall portion (22;122) of the handle case (20;120), and a base end portion (31a;131a) of the elastic piece (31;131) is connected to the peripheral wall portion (22;122).