Abstract: An epidermic injection device includes a flexible and elastic storing chamber. The storing chamber includes a flat contact surface for contacting with a user's skin. A plurality of thin needles are distributed over the contact surface with their sharp tips outward and perpendicularly projected from the contact surface. Each needle has an internal passage communicating with a hollow space in the storing chamber. Liquid medicine is first injected into the hollow space to generate an internal pressure in the storing chamber. When the device is attached at the flat contact surface to the user's skin or mucous membrane, the needles pierce through the skin and the internal pressure urges the liquid medicine to automatically slowly flow through the needles into the skin. The device largely reduces sharp pains that would be otherwise caused by a conventional syringe during injection, and is particularly suitable for use in epidermic local anesthesia.