As the public interests in about the importance of tidal flat have been increasing, a number of efforts to designate a tidal flat whose protection is demanded as a Protected Wetland Area (PWA) are also made. In particular, the Boseong tidal flat has been visited by a large number of visitors and widely accepted as a good example of well-managed PWA since it was designated as a PWA in 2003 and registered as a Ramsar site in 2006. It is in such situations that we attempt to assess the non-market value of the Boseong tidal flat by employing the contingent valuation survey that has been widely used in valuing the non-market goods. To this end, a survey of randomly sampled 1,000 households was implemented. A spike model is applied to analyzing the willingness to pay (WTP) data to deal with zero observations. The results show that the annual mean WTP is 5,569 won per household and statistically significant. Expansion of the value to the national population gives us an estimate of 95.5 billion per year. This useful information could be crucially utilized in decision-making about conserving and managing the Boseong tidal flat.