To provide construction machinery which facilitates access to electric components during the operation of the maintenance of the electric components, which enables the operation of the maintenance of the electric components to be performed in a comfortable position, and which is superior in waterproof properties for the electric components.

This construction machinery includes a controller which has a storage section for storing a program for controlling the various operations of the construction machinery, and for storing diagnostic information on the self-diagnosis of the various operations of the construction machinery. In the construction machinery, a trim 23 of a cab is partially equipped with a storage box 24 which is provided with a front opening 25; an electric component-assembled substrate 27, in which a fuse box 28 provided with a fuse and the like for the various electric components, a writing connector 29 connected to an external writing device for rewriting contents in the storage section, and reading connectors 30a and 30b connected to an external reading device for reading the diagnostic information stored in the storage section are assembled, is fixedly mounted in the storage box 24; and the front opening 25 is provided with an openable/closable cover 26.