Connecting structure and wearable device

A connecting structure comprising:

• a connecting pin that has a first portion, a second portion thicker than the first portion, and a step between the first portion and the second portion and connects a connecting object and a connected object to each other by being inserted into a first insertion hole of the connecting object and a second insertion hole of the connected object;
• a pin catch that moves in a recess in one of the connecting object and the connected object in moving directions that are not parallel to an extending direction of an insertion hole of the one of the connecting object and the connected object and has a pin engagement portion that engages the step of the connecting pin, the insertion hole being one of the first insertion hole and the second insertion hole;
• a biasing member that biases the pin catch in a direction among the moving directions;
• and
• a holder that is provided on the one of the connecting object and the connected object and transitions, in response to user operation, to one of a first state in which the holder holds the pin catch in cooperation with the biasing member and a second state in which the pin catch is detachable from the recess, wherein:
• the pin catch moves in the recess between a first position and a second position that is different from the first position in the moving directions;
• upon the pin catch being in the first position in response to cooperation of the biasing member and the holder, the connecting pin engages the pin engagement portion at the step;
• upon the pin catch being in the second position in response to user operation against biasing force by the biasing member, the second portion passes through the pin engagement portion;
• the pin catch has an abutment;
• upon the pin catch being in the second position, the abutment abuts on a wall of the recess, the wall intersecting a line through the recess at a point that is in the moving directions;
• the biasing member is a compression coil spring;
• and
• the abutment is located inside the compression coil spring.