Finemet amorphous alloys are in the focus of interest because they become especially good soft magnetic materials after partial nanocrystallisation. Cu is an important component of the alloy, however, its role in the recrystallisation process is still not clear. The soft magnetic properties may be further improved by increasing the Cu content, however, by the normally used quenching preparation method, the ratio of Cu remains under 5 at.%. We prepared amorphous thin film samples with Cu content up to 35 at.% by co-sputtering an original finemet ribbon and simultaneously a Cu target onto a thermally oxidised Si(100) substrate. The samples were characterised by XRD, UPS, and XPS. According to the XRD measurements, there was no significant Cu precipitation. The Cu 3d originated states of the valence band gradually developed towards the bulk Cu valence band density of states, although even in the sample containing 35 at.% Cu, significant differences were observed when compared to the bulk data.