We analyze, for the first time, the scaling behavior of the photospheric ve
rtical velocity field. Our analysis is based on data collected by the Itali
an Panoramic Monocromator (IPM) mounted at the THEMIS telescope at the Span
ish "Observatorio del Teide" (Tenerife) of the Institute de Astrofisica de
Canarias. We investigate the occurrence of scaling in the cancellations bet
ween downflow and upflow of the vertical velocity field, showing that the f
ield possesses well pronunced sign-singularity in the range of scales from
more than 10 Mm down to the granulation scale.