Relations between both countries are strong (on a North Korean scale). As an example, in the past some North Koreans visited a czech nuclear installation.
According to wikileaks:
The delegation visited the Czech nuclear power facility at Temelin on 20 October. Officials at the MFA and the Prime Minister’s office, as well as Speaker of Parliament Lubomir Zaoralek, were well aware of USG views urging the Czechs to cancel this stop (ref B). MFA staff report that (former) Deputy Minister of Foreign Affairs Kolar raised this several times with Zaoralek. Ambassador passed a strong message to Zaoralek reminding him of our concerns. Zaoralek’s staff replied that the Speaker was able to limit the visit to only “non-sensitive” areas of the facility, but “for political reasons” was not able to force Vice Speaker Filip to cancel the visit completely. MFA staff also indicate that Zaoralek did not, as he intended, tell the DPRK del that he expected them to permit Czech officials to visit the facility at Yongbyon. This was allegedly because a Czech press report on 18 October had claimed that Zaoralek intended to “trick” the North Koreans into agreeing to a visit to Yongbyon.
It has to be underline that there is a North Korean restaurant in Prague, there is a Czech embassy in Pyongyang. North Korean based are trying to make exhibitions of the North Korean art in Czech Republic. In the past a lot of North Koreans were working in Czech, and Czech were (with Poland) belonging to the Neutral Nations Supervisory Commission which was involved in the management of the border between North and South Korea.
The former ambassador of the DPRK to the Czech Republic was Ri Pyong Gap, a 60 years old gentleman who was perfectly speaking in english, his diplomatic background was also used during secret negotiations between Europe and the DPRK Interestingly Ri Pyong Gap used to work at the nuclear desk of the DPRK MOFA before moving to Prague. He came back to Pyongyang in 2011 and was replaced by Ri Kwang Gil.
A former wife of a czech diplomat based in Pyongyang explain her experience in the film below: