An electronic apparatus that transmits error information about setting of a block size to a host device without making a design of the host device complicated and a control method thereof, are provided. The electronic apparatus of the present invention has: an interface section that transmits/receives a command, a response and data to/from the host device and when the data is a predetermined length or more, executes multi-block transmission; a data buffer; and a storage section that stores information about a block size, wherein when the interface section receives a block size setting command transmitted from the host device and the block size is larger than a capacity of the data buffer, it transmits a response including error information about incapability of accepting the block size at the time which has a predetermined relation to the block size setting command.