To provide a board unit having an insertion-extraction handle locking structure with which a desired locking force can be easily generated and the locking force is hardly lowered, and which is low in production cost. An insertion-extraction handle 5 is rotatably supported by a panel body 4. A spring unit 6 is resiliently held in a spring receiving hole 45 formed in the panel body 4 and has a first spring part 61 which, when a stopper part 53 of the insertion-extraction handle 5 is inserted into the spring receiving hole 45, applies a resistance to the insertion of the stopper part 53, and which, when the stopper part 53 is extracted from the spring receiving hole 45, applies a resistance to the extraction of the stopper part 53. Second spring parts 62 of the spring unit 6 are configured to generate a resistance to removal of the spring unit 6 which is greater than the resistance to the insertion of the stopper part 53 between the spring unit 6 and the spring receiving hole 45 when the stopper part 53 is inserted into the spring receiving hole 45 and to generate a resistance to removal of the spring unit 6 which is greater than the resistance to the extraction of the stopper part 53 between the spring unit 6 and the spring receiving hole 45 when the stopper part 53 is extracted from the stopper receiving hole 45.