The invention discloses an ultrasonic apparatus and an image capturing method. The image capturing of a needle-knife (11) and needle-knife
visualization are realized by sending ultrasonic signals in the direction of the
cutting part (111) of the needle-knife (11), converting the ultrasonic return signals into ultrasonic images and outputting the images through a display circuit (14). Further more, the ultrasonic apparatus make the
irradiation direction of the ultrasonic beams lean to the
motion direction of the
cutting part (111) of the needle-knife (11) by measuring the derivation angle of the needle-knife (11) and adjusting the
irradiation direction of the irradiated ultrasonic beams. According to the direction, the
cutting part (111) of the needle-knife (11) is assured to be in the energy band generated by the ultrasonic wave all the time, thus, the cutting part of the needle-knife always presents in the ultrasonic images, and the needle-knife
visualization stability is further improved.