Please note that, recently, the address has been changed from Kruislaan to Science Park. In some maps however, the former address is still mentioned.
Then leave the A10 at junction S113, 'Watergraafsmeer' Ring East (ring Oost). At the end of the exit ramp, follow the directions to Watergraafsmeer/ Science Park. You are now driving on the Middenweg. Follow the signs to Science Park / Jaap Edenhal. Go to the right at the first big intersection, this is the Kruislaan. About 1 kilometer, after the tunnel under the railroad bridge, you are at Science Park Amsterdam.
See also the map at the right (zoom out).
By public transportation
Additionally, you can take the bus from the railway stations Amsterdam Amstel (line 40/240) or Amsterdam Muiderpoort (line 40). Time tables are available on the Amsterdam Public Transport (GVB) website.