Confidence: I'm as sure as I can be.
Notes: This looks like one of the spider parasitoids of the subfamily Pimplinae. This is a group of genera usually referred to as 'polysphinctines', which lay an egg on an active spider. The fore wing venation and the robust apical tarsal segments point to a polysphinctine, and the leg patterning is typical of various pimplines. Despite the fact it's a nice photo it's not very easy to progress further as I can't see various features.