An ultrasonic probe used for ultrasonic diagnosis apparatus. A plurality of ultrasonic transducer elements are provided in a convexity at the tip of a probe so as to constitute a convex array ultrasonic probe. The curvature radius of the convexity is set at not greater than 12 mm and the pitch of adjacent transducer elements is set at not greater than 1/30 of the curvature radius and a ratio Δ/Y is set at not greater than 1/35, where Y represents the beam focal distance and Δ represents the lateral resolution of the probe.