A response generation method comprising: a step (S101, S204) of recognizing a voice of a user by performing voice recognition processing based on voice information of the user acquired through a microphone, and generating character-string information of the recognized voice of the user; and a step (S104, S207) of analyzing a structure of the character-string information of the recognized voice of the user, characterized by further comprising: a step (S105, S209) of generating a free response sentence in response to the recognized voice of the user based on the analyzed structure of the character-string information, and a step (S106, S210) of outputting the generated free response sentence through a speaker; a step (S102, S205) of generating a repeat response sentence in response to the recognized voice of the user, and a step (S103, S206) of outputting the generated repeat response sentence through the speaker, wherein the repeat response sentence is generated by a parroting process of reproducing the recognized voice of the user based on the generated character-string information to exactly repeat the user's voice like a parrot, or an additional-word-ending-parroting process of extracting a keyword from the generated character-string information, and adding a specific additional word ending to the extracted keyword, and wherein the steps of generating and outputting the repeat response sentence are performed in parallel with the step of structure analysis and the steps of generating and outputting the free response sentence, and the processing cost of the repeat response sentence is lower than the processing cost of the free response sentence, such that the generated repeat response sentence is output during a response wait time before the generated free response sentence is output. a step (S101, S204) of recognizing a voice of a user by performing voice recognition processing based on voice information of the user acquired through a microphone, and generating character-string information of the recognized voice of the user; and a step (S104, S207) of analyzing a structure of the character-string information of the recognized voice of the user, characterized by further comprising: a step (S105, S209) of generating a free response sentence in response to the recognized voice of the user based on the analyzed structure of the character-string information, and a step (S106, S210) of outputting the generated free response sentence through a speaker; a step (S102, S205) of generating a repeat response sentence in response to the recognized voice of the user, and a step (S103, S206) of outputting the generated repeat response sentence through the speaker, wherein the repeat response sentence is generated by a parroting process of reproducing the recognized voice of the user based on the generated character-string information to exactly repeat the user's voice like a parrot, or an additional-word-ending-parroting process of extracting a keyword from the generated character-string information, and adding a specific additional word ending to the extracted keyword, and wherein the steps of generating and outputting the repeat response sentence are performed in parallel with the step of structure analysis and the steps of generating and outputting the free response sentence, and the processing cost of the repeat response sentence is lower than the processing cost of the free response sentence, such that the generated repeat response sentence is output during a response wait time before the generated free response sentence is output. a step (S105, S209) of generating a free response sentence in response to the recognized voice of the user based on the analyzed structure of the character-string information, and a step (S106, S210) of outputting the generated free response sentence through a speaker; a step (S102, S205) of generating a repeat response sentence in response to the recognized voice of the user, and a step (S103, S206) of outputting the generated repeat response sentence through the speaker, wherein the repeat response sentence is generated by a parroting process of reproducing the recognized voice of the user based on the generated character-string information to exactly repeat the user's voice like a parrot, or an additional-word-ending-parroting process of extracting a keyword from the generated character-string information, and adding a specific additional word ending to the extracted keyword, and wherein the steps of generating and outputting the repeat response sentence are performed in parallel with the step of structure analysis and the steps of generating and outputting the free response sentence, and the processing cost of the repeat response sentence is lower than the processing cost of the free response sentence, such that the generated repeat response sentence is output during a response wait time before the generated free response sentence is output.