A CE560EP Captain reported noticing a smell of electrical smoke on reaching cruise altitude. Crew declared emergency and diverted to a nearby airport.

Narrative

After level off [on a ferry flight] at FL400 the First Officer went to the back to put some charts away and smelled an acrid smell of electrical smoke; he asked me to confirm the smell; which I did. We donned oxygen masks; performed the emergency checklist; and then notified Center of our emergency. We started an emergency descent and Center gave us initial vectors to [diversion airport]. After analyzing the situation; we decided that it did not warrant dumping cabin pressure at a high altitude; as the smoke was not a big problem; more of a haze; and did not restrict our visibility. Center read us weather and NOTAM information and handed us off to Approach. They had crash fire rescue waiting our arrival; we landed; exited [the runway]; and evacuated the aircraft. The fire department inspected the airplane and noted the smell and haze lingering in the cabin. No apparent damage was visible. The aircraft was towed to [FBO] and put into the hangar. On a special note; I would like to comment that all the ATC Controllers did an outstanding job helpings us.