# NIntegrate throwing a non numerical error

I want to simulate the Fresnel diffraction and hence tried to define that function using NIntegrate. Even after using _?NumericQ it gives "evaluated to non numerical value error":

F[x_?NumericQ, ζ_?NumericQ] := NIntegrate[
(Exp[ I*2000*(((0.006)^2 + ζ^2)^(0.5) + (20^2 + (x - ζ)^2)^(0.5))]
) / ((0.006)^2 + ζ^2)^(0.5) // Evaluate
, {ζ, -0.003, 0.003}
] // Evaluate


What's the way out?

You defined function F[x_?NumericQ, ζ_?NumericQ] but never passed x as numeric value. (you are using numerical integration after all). In addition, ζ is your integration variable. So this can not be a number you pass to integrate.
f[x_?NumericQ]:=NIntegrate[(Exp[I*2000*(((0.006)^2+ζ^2)^(0.5)+

Now f[5] gives