Controller and portable electronic apparatus

A portable electronic apparatus, comprising:

• a controller including
• a housing, and
• at least one key provided for protruding and retreating movement on the housing,
• the key comprising:
• a body formed in a transversely elongated configuration elongated in a first direction, and
• a first stem positioned on one end side of the body in the first direction and extending along a third direction which is substantially perpendicular to the first direction and a second direction which is a protruding direction of the key from the housing, and the housing comprising:
• a biasing member for biasing the key in the second direction;
• and
• a first restricting portion positioned on the second direction side with respect to the first stem for engaging with the first stem biased by the biasing member, wherein
• one of the key and the housing has a second stem positioned on the other end side of the first direction and extending in the third direction while the other of the key and the housing has a guide portion which sandwiches an end of the second stem for guiding movement of the second stem in the second direction and a second restricting portion for engaging with the second stem biased by the biasing member.