A pillar structure (200, 300) for a biochip, the pillar structure being manufactured in one piece by injection molding, comprising: a substrate (210, 310) having a plate structure; a plurality of insertion pillars (220, 320) formed beneath of the substrate (210, 310) and protruded downward from a lower surface of the substrate (210, 310) so as to be inserted into corresponding wells; characterized in that it further comprises: a plurality of compensation pillars (230, 330) formed on the substrate (210, 310), and protruded upward from an upper surface of the substrate (210, 310), wherein each compensation pillar (230, 330) is aligned with a corresponding insertion pillar (220, 320), and is configured to compensate for a contraction of the insertion pillar (220, 320) caused by cooling after injection molding of the resin composition material which form the insertion pillars (220, 320), the compensation pillars (230, 330) and the substrate (210, 310) thereby preventing the upper surface of the substrate (210, 310) from being recessed, thus allowing for a more limited light distortion when analysing the biochip by microscopy through the pillar structure (200, 300), wherein each compensation pillar (230, 330) has a diameter having a ratio to a diameter of the corresponding insertion pillar (220, 320) within a range of 1 to 1.3. a substrate (210, 310) having a plate structure; a plurality of insertion pillars (220, 320) formed beneath of the substrate (210, 310) and protruded downward from a lower surface of the substrate (210, 310) so as to be inserted into corresponding wells; characterized in that it further comprises: a plurality of compensation pillars (230, 330) formed on the substrate (210, 310), and protruded upward from an upper surface of the substrate (210, 310), wherein each compensation pillar (230, 330) is aligned with a corresponding insertion pillar (220, 320), and is configured to compensate for a contraction of the insertion pillar (220, 320) caused by cooling after injection molding of the resin composition material which form the insertion pillars (220, 320), the compensation pillars (230, 330) and the substrate (210, 310) thereby preventing the upper surface of the substrate (210, 310) from being recessed, thus allowing for a more limited light distortion when analysing the biochip by microscopy through the pillar structure (200, 300), wherein each compensation pillar (230, 330) has a diameter having a ratio to a diameter of the corresponding insertion pillar (220, 320) within a range of 1 to 1.3. a plurality of compensation pillars (230, 330) formed on the substrate (210, 310), and protruded upward from an upper surface of the substrate (210, 310), wherein each compensation pillar (230, 330) is aligned with a corresponding insertion pillar (220, 320), and is configured to compensate for a contraction of the insertion pillar (220, 320) caused by cooling after injection molding of the resin composition material which form the insertion pillars (220, 320), the compensation pillars (230, 330) and the substrate (210, 310) thereby preventing the upper surface of the substrate (210, 310) from being recessed, thus allowing for a more limited light distortion when analysing the biochip by microscopy through the pillar structure (200, 300), wherein each compensation pillar (230, 330) has a diameter having a ratio to a diameter of the corresponding insertion pillar (220, 320) within a range of 1 to 1.3.