1. A speech recognition apparatus for allowing setting by speech, comprising: an input unit configured to input a setting instruction by speech; a speech interpretation unit configured to recognize and interpret contents of the setting instruction by speech to generate first structured data containing candidates of the interpretation result; an instruction input detecting unit configured to detect a setting instruction input by a user; an instruction input interpretation unit configured to interpret contents of the setting instruction input to generate second structured data; and a selection unit configured to select one of the interpretation candidates contained in the first structured data on the basis of the second structured data, wherein each interpretation candidate contained in the first structured data contains information of a setting item name and a setting value, and the second structured data contains information of a setting item name; and further comprising: a setting window control unit configured to display a setting window corresponding to the setting instruction input when said instruction input detecting unit detects the setting instruction input, said setting window control unit inhibiting display of the setting window when said speech input unit inputs the setting instruction.