PROBLEM TO BE SOLVED: To provide ultrasonic diagnostic equipment capable of accurately adjusting the focus of a luminance image by calculating an accurate environmental sonic velocity, without reference to the state of a diagnostic region of a subject.SOLUTION: Ultrasonic diagnostic equipment includes: an ultrasonic transmission/reception unit which transmits an ultrasonic beam to a subject and which outputs reception data by receiving an ultrasonic echo produced by having the ultrasonic beam reflected from the subject； and an environmental sonic velocity calculation unit which acquires first reception data having a frequency lower than second reception data for generating a luminance image of the subject and used to calculate an environmental sonic velocity being a sonic velocity in the subject, and which calculates the environmental sonic velocity by analyzing the acquired first reception data.【課題】被検体の診断部位の状態に係わらず、正確な環境音速を算出して、正確に輝度画像のフォーカスを合わせることができる超音波診断装置を提供する。【解決手段】超音波診断装置は、超音波ビームを被検体に送信し、超音波ビームが被検体から反射した超音波エコーを受信して受信データを出力する超音波送受信部と、被検体の輝度画像を生成するための第２の受信データよりも低周波のデータであり、被検体内の音速である環境音速を算出するための第１の受信データを取得し、取得した第１の受信データを解析して、環境音速を算出する環境音速算出部とを備える。【選択図】図９
