Provided is a tissue mimicking phantom technology capable of controlling an ultrasonic echo intensity and hardness and offering excellent stability. A tissue mimicking phantom includes a first portion and a second portion which is incorporated in the first portion and whose hardness and/or ultrasonic echo intensity is different from that of the first portion. The first portion and second portion are gel structures that are formed with a covalent bond of macromolecular strands or a chemical bond that is as strong as the covalent bond. The gel structure has a solid scatterer (for example, metal-oxide microparticles) dispersed therein. The first portion and second portion exhibit mutually different hardness levels and ultrasonic echo intensities.