A container has a grounding portion that is free from sink and can prevent sink from occurring, so that it can secure its self-standing ability. The bottle-shaped container made of synthetic resin comprising a neck (3), a body (5) and a bottom (7), said bottom (7) including a grounding portion (81), said bottom (7) being formed at a center thereof with a central bulged section (77) protruding inwardly, said container showing a polygonal transversal cross section, characterized in that a peripheral bottom wall (79) is formed between an outer periphery of the central bulged section (77) and the grounding portion (81), said peripheral bottom wall (79) forming a step located below the central bulged section (77) and above the grounding portion (81), and said grounding portion (81) is provided with a recess (85) in a portion formed with an orientation magnification which is smaller than an orientation magnification with which a portion on and along a diagonal line (L) is formed.