Mouse pups are invaluable model animals for understanding the molecular and neural basis underlying behavioral development. Stereotaxic operations with anesthetic control are useful tools in systems neuroscience. However, there are no commercially available anesthetic or stereotaxic devices for mouse pups. Current devices have several problems such as invasive approach for stabilization, poor sanitary control, and less flexibility to combine other surgical apparatuses. Here, we developed an inhalation anesthetic device equipped with stereotaxic function for mouse pups, by using polydimethylsiloxane (PDMS). PDMS is tolerant to heat and water exposure, and soft enough to cut or make a hole. The anesthetic and the stereotaxic parts were fabricated from the three-dimensional computer-aided design (3D CAD) data obtained from the head of a real mouse pup. To confirm its utility, a tracer was injected into the brain. We were able to anesthetize and stabilize pups at once in a non-invasive manner using the PDMS device. The histological staining revealed that tracer injection was successful. Our device was compatible with various types of commercial stereotaxic and anesthetic apparatuses via trimming and tube insertion, respectively. To our knowledge, this is the first report of a device that can stabilize the mouse pup's head with the non-invasive manner and functions as an inhalation anesthetic device that can be sterilized. The present fabrication method will provide a handy and functional instrument for stereotaxic operations in animal models at various developmental stages.