  We examine the particle production during tunneling in quantum cosmology. We
consider a minisuperspace model with a massive, conformally coupled scalar
field and a uniform radiation background. In this model, we construct a
semiclassical wave function describing a small recollapsing universe and a
nucleated inflating universe (``tunneling from something''). We find that the
quantum states of the scalar field in both the initial and the nucleated
universe are close to the adiabatic vacuum, the number of created particles is
small, and their backreaction on the metric is negligible. We show that the use
of the semiclassical approximation is justified for this wave function. Our
results imply that the creation of the universe from nothing can be understood
as a limit of tunneling from a small recollapsing universe.
