Liquid medication injection device

A liquid medicine injection device, comprising:

• a casing;
• a button exposed outside of the casing;
• a needle holder located in the casing and coupled to a needle, wherein the needle holder is configured to linearly move by actuation of the button;
• a spring interposed between the button and the needle holder;
• and
• a guiding member located in the casing and configured to support the needle holder,
• wherein the needle holder is configured to be spaced apart from a base of the casing and supported by the guiding member in a first state,
• wherein the needle holder is configured to be driven toward the base by an elasticity of the spring while being transformed into a second state, after the button is rotated with respect to the first state, and
• wherein the needle holder comprises:
• a first support that is supported by the guiding member in the first state, and
• a guiding groove provided to be adjacent to the first support, wherein the guiding member is configured to pass through the guiding groove after the button is rotated with respect to the first state.