To provide a hinge device of a mobile device enabling a reduction in production cost by facilitating assembly without increasing the number of parts and easily providing complicated operations and characteristics.

This hinge device of the mobile device comprises a first hinge part 4 connecting a first casing 2 and a second casing 3 forming the mobile device to each other rotatably about a first hinge pin and comprising a case body 41, the first hinge pin 42, and a first cam mechanism 6 and a second hinge part 5 connecting the first casing to the second casing rotatably about a second hinge pin extending in a direction orthogonal to the first hinge pin and comprising the second hinge pin 51, a hinge body 52, and a second cam mechanism 7. The second casing 3 is fitted to the first hinge part 4 so that a clearance 11 can be produced between the the second casing and the first casing 2 and rotatably about the first hinge part 4 even in the rotating range of 0 to 180° of the second casing by the second hinge part 5. A double face cam body having a double face cam part is used for at least either of the first cam mechanism 6 and the second cam mechanism 7.