A general definition of convolution between two arbitrary tempered ultradis
tributions is given. When one of the tempered Ultradistributions is rapidly
decreasing this definition coincides with the definition of J. Sebastiao e
Silva. The product of two arbitrary distributions of exponential type is d
efined via the convolution of its corresponding Fourier transforms. Several
examples of convolution of two tempered ultradistributions and singular pr
oducts are, given. In particular, we reproduce the results obtained by A. G
onzales Dominguez nd A. Bredimas.