The present invention relates to a pharmaceutical injection device, and it is an object thereof to prompt the user to replace the injection needle as needed. To achieve this object, the present invention is configured such that a needle detector switch 8 that directly or indirectly detects the mounting of an injection needle to a pharmaceutical syringe 5 is provided to a main case 2, this needle detector switch 8 is connected to a controller 21, and the controller 21 displays on a display component 19 an injection needle removal message that directly or indirectly prompts the user to remove an injection needle 6 from the pharmaceutical syringe 5 when the mounting of the injection needle 6 to the pharmaceutical syringe 5 has been detected by the needle detector switch 8 in the switching off the a power switch 16.
