A method of controlling a dialogue system including a processor, a memory, an audio input apparatus, an audio output apparatus, and a touch panel including a display unit configured to process touch input, the method comprising: - an inquiry step of generating, by the processor, inquiry information including at least one option, and outputting the inquiry information from one of the audio output apparatus and the touch panel; - an input step of receiving, by the processor, an answer to the inquiry information through one of the audio input apparatus and the touch panel; - a guidance step of generating, by the processor, candidates for guidance information that correspond to the answer, and outputting the candidates for the guidance information from one of the audio output apparatus and the touch panel; and - a mode switching step of choosing, by the processor, a mode suitable for a running status of the dialogue system from a first dialogue mode, in which options being areas for receiving the touch input based on the inquiry information are output to the touch panel, and a second dialogue mode, in which a comment (511, 514, 518) presented to the user based on the inquiry information is output from one of the touch panel and the audio output apparatus, each of the inquiry step and the guidance step comprising using one of the first dialogue mode and the second dialogue mode that is chosen in the mode switching step, characterized in that: the running status of the dialogue system comprises sensor information detected by an image information obtaining module, wherein the sensor information comprise the number of users and the position of each user who uses the dialogue system, and wherein the mode switching step comprises choosing one of the first dialogue mode and the second dialogue mode based on the sensor information. - an inquiry step of generating, by the processor, inquiry information including at least one option, and outputting the inquiry information from one of the audio output apparatus and the touch panel; - an input step of receiving, by the processor, an answer to the inquiry information through one of the audio input apparatus and the touch panel; - a guidance step of generating, by the processor, candidates for guidance information that correspond to the answer, and outputting the candidates for the guidance information from one of the audio output apparatus and the touch panel; and - a mode switching step of choosing, by the processor, a mode suitable for a running status of the dialogue system from a first dialogue mode, in which options being areas for receiving the touch input based on the inquiry information are output to the touch panel, and a second dialogue mode, in which a comment (511, 514, 518) presented to the user based on the inquiry information is output from one of the touch panel and the audio output apparatus, each of the inquiry step and the guidance step comprising using one of the first dialogue mode and the second dialogue mode that is chosen in the mode switching step, characterized in that: the running status of the dialogue system comprises sensor information detected by an image information obtaining module, wherein the sensor information comprise the number of users and the position of each user who uses the dialogue system, and wherein the mode switching step comprises choosing one of the first dialogue mode and the second dialogue mode based on the sensor information.