A copy of the storage trap from the PUMA experiment is being used in Darmstadt to carry out development work, whose findings can be applied directly to the PUMA trap at CERN. Now, for the first time, electrons have been successfully captured and visualized with the help of a camera. The motion of the electrons inside the Penning trap is dominated by the magnetron motion, which produces the circle visible in the image. The electrons play a crucial role in the PUMA experiment, as they will be used to cool the antiprotons, which enables the long-term trapping and the transport of the antiprotons.