Today when I went into the workshop I had to light the fire because, despite reasonably sunny weather, the temperatures are really low. And this little fellow was sitting on one piece of wood and he gave me quite a start, for I have mistaken him for a wasp. Which is the point of its coloration, of course.
Unfortunately, I was only able to make these two pictures. The beetle was quite sluggish in the cold workshop, but when I took it outside in the sun, it warmed up quickly and flew off before I could make more with better camera settings. I hope my entomologist friend will be able to identify the species. Preliminarily I think it is some species of longhorn beetle that has emerged from a pupa in firewood.