An ultrasound diagnostic apparatus comprising: an ultrasound probe; an imaging unit configured to transmit an ultrasound beam to and receive an ultrasound echo from an imaging part of a subj ect using the ultrasound probe and to convert a received signal output from the ultrasound probe into an image to generate a B-mode image of the subject; a display unit; a collation pattern memory configured to store a plurality of collation patterns corresponding to a plurality of examination parts of the subject in advance; a confidence degree calculation unit configured to read the plurality of collation patterns from the collation pattern memory, to collate the B-mode image generated by the imaging unit with each of the plurality of read collation patterns to perform part recognition, and to calculate degrees of confidence for the examination parts corresponding to each of the read collation patterns; and a dialogue display control unit configured to determine whether to display, on the display unit, a dialogue for making a user check which of the plurality of examination parts, for which the degrees of confidence have been calculated, is the imaging part of the subject on the basis of the degrees of confidence and to display the dialogue on the display unit on the basis of a determination result; characterized in that, in a case in which the degree of confidence calculated for the collation pattern corresponding to an examination part that has been examined among the calculated degrees of confidence is greater than a predetermined threshold value, the dialogue display control unit is configured to display the dialogue on the display unit. an ultrasound probe; an imaging unit configured to transmit an ultrasound beam to and receive an ultrasound echo from an imaging part of a subj ect using the ultrasound probe and to convert a received signal output from the ultrasound probe into an image to generate a B-mode image of the subject; a display unit; a collation pattern memory configured to store a plurality of collation patterns corresponding to a plurality of examination parts of the subject in advance; a confidence degree calculation unit configured to read the plurality of collation patterns from the collation pattern memory, to collate the B-mode image generated by the imaging unit with each of the plurality of read collation patterns to perform part recognition, and to calculate degrees of confidence for the examination parts corresponding to each of the read collation patterns; and a dialogue display control unit configured to determine whether to display, on the display unit, a dialogue for making a user check which of the plurality of examination parts, for which the degrees of confidence have been calculated, is the imaging part of the subject on the basis of the degrees of confidence and to display the dialogue on the display unit on the basis of a determination result; characterized in that, in a case in which the degree of confidence calculated for the collation pattern corresponding to an examination part that has been examined among the calculated degrees of confidence is greater than a predetermined threshold value, the dialogue display control unit is configured to display the dialogue on the display unit.